Does anyone else feel like Pokémon Sun and Moon ruined Pokémon?

Answers

No that's just the fanbase talking bull crap like they did to every other generation since Black and White. They're not the only ones that say their games ruined the franchise. Take SEGA for example. The fans always have different opinions and make every game look bad including the classics. They recently started hating on Sonic Mania and Sonic CD for no reason.

sun and moon was the best pokemon game since platinum (not counting remakes of course). it breathed new life into the franchise, the alola forms made otherwise forgettable pokemon now highly sought after, the trails were a fun and engaging way to meet new characters, much better than the gym leaders who i never felt a real connection with, the new mechanics such as sos training were great and made getting pokemon with hidden abilities or shinies much more accessible while still being reasonably difficult.
honestly the only downside is that it wasn't longer. i would have loved having 8 islands like hawaii in real life rather than 4

Not at all, in fact I enjoyed the game, it's setting, and the fact that it at least has some amount of challenge compared to the older trivially easy titles. It sure as hell was better then X/Y, which my dog could play reasonably well.

You probably just have extremely narrowed tastes that the game didn't reach for one reason or another, or you're just an extremely vocal fanboi who hates everything.

Sun and moon was so boring gave up after beating first gym leader or what ever they are in the new game not going into detail why it was so terrible pretty sure other people can list the problems im never going back if i see another Hawaii look to Pokemon again

More like, Gamefreak ruined Pokemon themselves, despite all of their money from the franchise. Even the new Let's and Go game were a mere cashgrab that aimed for the casuals, with some connection with Pokemon Go, no wild Pokemon battles, and no competitive stuffs.

They were always play it safe, using old formulas and with very little innovation. Not to mention they were late to jump the HD gaming, despite Nintendo has went there since 2012.

Sure, there's the 2019 title that were aimed for the "hardcore" fans. But I won't be surprised if its just an another dissapointment.